Another no power question

[wakeboardin2k4]

Hey Guys

Having a problem with my truck not having any power at certain times.

First start up of the day goes ok. Idles poorly though. I leave the driveway and 300 yards down the road the truck starts loping really badly and misfiring until I have absolutely nothing left for power and then the truck dies. I sit for a few seconds, crank it over a for 10 seconds, 2 or 3 times and it fires back up but sounds like a diesel would if it ran out of fuel. Barking and shaking away and then it smooths out. I go down the road after that first shut down and the truck will run, like crap of course, until I approach a hill. When that first hill is presented to the truck it does all the same things that it did when I first leave the driveway. Backfires till it dies. Crank it over a bunch, idles crappy then I keep going up the hill, make it 100 yards, andddd repeat the process.

Ive changed the CPS a few weeks ago for something else.

New fuel filter just the other day because I figured Id start with that, no improvements tho.

Im a boat mechanic by trade and understand how diesels work, but I don't work on diesels on a daily basis, so thats why I came to the pros.

If I were to guess id go with either lift pump or fuel pressure regulator?

Anyone else have ideas?

[White95f250]

I'm not doubting your knowledge or skills but is the oil level ok and how old is the oil? What were the other problems you had with it?

[wakeboardin2k4]

Originally Posted by White95f250

I'm not doubting your knowledge or skills but is the oil level ok and how old is the oil? What were the other problems you had with it?

Trust me I take 0 offense to debating my skills! Oil level is good and oil is about 1600 miles old.

Previous issue was that the truck wouldn't start. I changed the crank sensor and it worked fine for a 1600 mile trip to SC and back from NJ

[White95f250]

What was the fuel level when this happened?

I had the same symptoms for the most part and it was cause I got air in the line. All said and done I put it in neutral and gave it a few good revs to force the air out and now all is good.

[wakeboardin2k4]

I've switched back and forth between the two tanks. 1 is at a quarter tank the other is full. I thought air in the lines at first also but I've managed to put 34 miles on the truck with this issue attempting to figure it out. I would guess after that amount of driving the air would work it's way out? Unless there's something causin constant air in the lines

[Chop]

Could be the lift pump,you can check pressure at schrader valve.Another thought comes to mind the Idm may have water in it giving you the random issue.Too me ,these are the cheapest and easiest tests.I've seen many a post on the watered idm,guys remove them and can hear it sloosh.

[justinmix]

I would start with checking fuel pressure. Mechanical fuel pumps are kind of goofy. It might be making enough fuel pressure to run but when you put it under load it's dying off.

Fuel pressure is easy to check. I wouldn't be running it much though. Low fuel pressure is hard on injectors.

[White95f250]

You can drive it all day with air in the line and it running like crap. But you must FORCE the air out by putting it in neutral and giving it a few good revs.

But I would do the above tests first and if it is all ok then try the rev procedure and see if anything changes.

[Welderman2008]

not to thread jack but what if u have e-fuel and u have a new IDM....

[wakeboardin2k4]

I checked the fuel pressure at the shrader valve with the pressure gauge and had a very consistent 65 +/- psi at idle and while reving it up (no load) but was still not running right at all.

I know that there are many cases of IDMs causing a problem. However I do not know where the IDM...sorry its not something i see on a daily basis working on boats so im behind the 8 ball on where diesel specific parts are on the ol' 7.3

Originally Posted by White95f250

You can drive it all day with air in the line and it running like crap. But you must FORCE the air out by putting it in neutral and giving it a few good revs.

But I would do the above tests first and if it is all ok then try the rev procedure and see if anything changes.

I tried this also just to make an easy diagnosis...no such luck